Oral care compositions

ABSTRACT

Described herein are oral care compositions comprising a crosslinked polyvinylpyrrolidone complexed with hydrogen peroxide, together with particular co-polymers as additional excipients; including some embodiments which further comprise a calcium abrasive.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/997,430, filed Jun. 24, 2013, now allowed, which is a national stageentry under 35 USC §371 of International Patent Application No.PCT/US2011/038874, filed Jun. 2, 2011, which is a continuation-in-partof International Patent Application No. PCT/US2010/061711, filed Dec.22, 2010, the contents of which are hereby incorporated by reference intheir entirety.

BACKGROUND

Dentifrice formulations comprising peroxide are known and useful forcleaning and whitening teeth. The peroxide can bleach the teeth, removestains, and kill cariogenic bacteria. However, peroxide compounds arehighly reactive, and consequently difficult to formulate. Moreover,hydrogen peroxide can spontaneously decompose to form oxygen gas (O₂)and water, so that on storage, the dentifrice containers may bloat,burst or leak, and the remaining formulation will not have enoughperoxide remaining to clean and whiten teeth effectively. Some initiallycomprise very high levels of peroxide, which decomposes over time, sothat the exact amount of peroxide delivered on application is variableand largely depends on how long and under what conditions the dentifricehas been stored.

Abrasives comprising calcium phosphate salts, such as calciumpyrophosphate, dicalcium orthophosphate dihydrate, tricalcium phosphate,and calcium polymetaphosphate are useful in dentifrice materials, as inaddition to providing an abrasive action which cleans the teeth, suchsalts provide a source of calcium and phosphate which can help build andrepair the teeth. Calcium salts such as calcium carbonate are alsocommonly used as abrasives. However, under oxidizing conditions, calciumions can readily form calcium peroxide (CaO₂) and calcium oxide (CaO,also known as (quicklime), which is highly reactive and corrosive,reacting exothermically with water for example to form calcium hydroxide(Ca(OH)₂). Thus dentifrices using calcium salts are not preferred forformulation with peroxide.

Abrasive-free dentifrices comprising peroxide also present formulationchallenges. While the problem with interaction with the abrasive isremoved, the peroxide may still react with other components of theformulation and/or decompose to release O₂.

By exposure to aqueous environments, as in the oral cavity, the PVP-H₂O₂dissociates into individual species (PVP polymer and H₂O). The PVP-H₂O₂complex is generally comprised of about 80% by weight polyvinylpyrrolidone and 20% by weight H₂O₂. Single phase whitening dentifricecompounds comprising PVP-H₂O₂ complexes are described, e.g., inWO/2007/037961, and its parent US Pub. No. US 2007-0071695 A1, thecontents of which are incorporated herein by reference.

While there are numerous publications of gels comprising peroxide, suchgels are generally for use with dental trays or strips, rather than forapplication using a toothbrush, and such gels are not necessarilysuitable for use as a dentifrice because they may adhere to thetoothbrush, rather than rinsing off easily, and leave the consumer withan unpleasant experience due to the lack of foaming provided by theproduct.

There is thus a need for improved peroxide dentifrice formulations thatare stable for long-term storage and are suitable for everyday consumeruse.

SUMMARY

In some embodiments, the present invention provides oral carecompositions that are stable during long term storage and remaineffective to clean and whiten teeth. In some embodiments, the inventionprovides an oral care composition comprising: (i) a crosslinkedpolyvinylpyrrolidone complexed with hydrogen peroxide and (ii) anabrasive. In some embodiments, the abrasive is a calcium abrasive. Inother embodiments, the invention provides an oral care compositioncomprising a crosslinked polyvinylpyrrolidone complexed with hydrogenperoxide, and a stabilizing amount of additional linear and/orcrosslinked polyvinylpyrrolidone. In further embodiments, the inventionprovides an oral care composition comprising (i) a cross linkedpolyvinylpyrrolidone complexed with hydrogen peroxide, and an ethyleneoxide, propylene oxide block co-polymer of formula (ethyleneoxide)_(x)-(propylene oxide)_(y) wherein x is an integer of 80-150 and yis an integer 30-80, having an average molecular weight of greater than5000 Da. Further embodiments of the invention will be apparent from thedetailed description and the examples.

DETAILED DESCRIPTION

As used throughout, ranges are used as shorthand for describing each andevery value that is within the range. Any value within the range can beselected as the terminus of the range.

All references cited herein are hereby incorporated by reference intheir entireties.

In the event of a conflict in a definition in the present disclosure andthat of a cited reference, the present disclosure controls.

As used herein, the phrase “unacceptable level of phase separation”refers to the extent of phase separation that: (1) occurs when a sampleis centrifuged at 2050 rpm in a LumiSizer 110 analytical centrifuge; and(2) is predictive of a product that possesses unacceptable physicalstability.

In some embodiments, the present invention provides oral carecompositions comprising a crosslinked polyvinylpyrrolidone complexedwith hydrogen peroxide, and a stabilizing amount of additional linearand/or crosslinked polyvinylpyrrolidone and/or with an ethylene oxide,propylene oxide block co-polymer of formula (ethyleneoxide)_(x)-(propylene oxide)_(y) wherein x is an integer of 80-150 and yis an integer 30-80, having an average molecular weight of greater than5000 Da. Some embodiments further comprise an abrasive. In someembodiments, the abrasive is a calcium abrasive.

Accordingly, the invention provides a dentifrice comprising (i) acrosslinked polyvinylpyrrolidone complexed with hydrogen peroxide and(ii) an ethylene oxide, propylene oxide block co-polymer of formula(ethylene oxide)_(x)-(propylene oxide)_(y) wherein x is an integer of80-150, e.g. 100-130, e.g. about 118, and y is an integer 30-80, e.g.about 60-70, e.g. about 66, having an average molecular weight ofgreater than 5000, e.g., 8000-13000 Da, e.g. about 9800. In someembodiments, the invention provides a toothpaste comprising an abrasive,e.g., a calcium abrasive. In other embodiments, the invention providesan abrasive-free gel.

In one embodiment, the invention provides a dentifrice comprising (i) acrosslinked polyvinylpyrrolidone complexed with hydrogen peroxide and(ii) a calcium abrasive, in a dentifrice carrier.

For example, the invention provides Composition 1, a toothpastecomprising (1) a whitening complex comprising crosslinkedpolyvinylpyrrolidone complexed with hydrogen peroxide, (ii) a calciumabrasive, e.g.,

-   -   1.1. Composition 1 wherein the whitening complex contains about        10-30%, e.g., 15-25%, for example about 17-22% of hydrogen        peroxide by weight, and about 5-15%, for example about 7-12%        total nitrogen by weight; for example, having substantially the        same specifications as Polyplasdone® XL-10, e.g., Polyplasdone®        XL-10F, e.g., available from International Specialty Products        (Wayne, N.J.);    -   1.2. Composition 1 or 1.1 wherein the calcium abrasive comprises        a calcium phosphate salt, e.g., calcium pyrophosphate, dicalcium        orthophosphate dihydrate, tricalcium phosphate, and calcium        polymetaphosphate;    -   1.3. Any of the foregoing compositions wherein the calcium        abrasive comprises calcium pyrophosphate;    -   1.4. Any of the foregoing compositions wherein the calcium        abrasive comprises calcium carbonate;    -   1.5. Any of the foregoing compositions wherein the total amount        of hydrogen peroxide by weight of the composition is 0.5-3%,        e.g., 0.75-1.5%, e.g. about 1%;    -   1.6. Any of the foregoing compositions which contains less than        2% water, e.g., less than 1% water, e.g., is substantially        anhydrous;    -   1.7. Any of the foregoing compositions comprising polymer        thickeners selected from (i) polyethylene glycol, (ii)        polyethylene glycol polypropylene glycol block co-polymers        having a molecular weight of at least 5000, and (iii)        combinations thereof;    -   1.8. The preceding composition comprising an ethylene oxide,        propylene oxide block co-polymer of formula (ethylene        oxide)_(x)-(propylene oxide)_(y) wherein x is an integer of        80-150, e.g. 100-130, e.g. about 118, and y is an integer 30-80,        e.g. about 60-70, e.g. about 66, having an average molecular        weight of greater than 5000, e.g., 8000-13000 Da, e.g. about        9800;    -   1.9. The preceding composition additionally comprising        polyethylene glycol of average molecular weight 400 to 800,        e.g., about 600 Da;    -   1.10. Any of the foregoing compositions additionally comprising        humectants, e.g. selected from glycerin, propylene glycol or a        combination thereof;    -   1.11. Any of the foregoing compositions additionally comprising        a tartar control agent, e.g., selected from tetrasodium        pyrophosphate (TSPP) and sodium tripolyphosphate (STPP);    -   1.12. Any of the foregoing compositions additionally comprising        a surfactant, e.g., sodium lauryl sulfate (SLS);    -   1.13. Any of the foregoing compositions additionally comprising        an antibacterial agent, e.g., triclosan;    -   1.14. An of the foregoing compositions additionally comprising        an antioxidant, e.g., but hated hydoxytoluene (BHT);    -   1.15 Any of the foregoing compositions comprising any or all of        the following ingredient classes and/or particular ingredients        by weight;

Humectants 25-40%, e.g. Glycerin 3-7%, e.g., about 5% Propylene glycol20-30%, e.g., about 25% Thickeners, e.g. Fumed silica 0-2%, e.g., about1.5% Polymers 10-30%, e.g., Ethylene oxide, propylene oxide 5-15%, e.g.,about 10% block co-polymer, avg. MW >5 kDa Polyethylene glycol 6005-15%, e.g., about 10% Polyvinylpyrrolidone 0-10% Whitener, 3-10%, e.g.,Crosslinked polyvinylpyrrolidone 3-10%, e.g., about 5.5% complexed with15-25% hydrogen peroxide Abrasive, 25-45%, e.g. Calcium pyrophosphate25-45%, e.g., about 35% Fluoride, 0-1%, e.g. Sodium monofluorophosphate0.5-1%, e.g., about 0.76% Surfactant, e.g., SLS  0-3% Tartar controlagent, e.g. TSPP 0.5-5%, e.g., about 2% Antioxidant, 0.01-5%, e.g. BHT0.03% Flavorings 0.1-5%  Water   <3%

-   -   1.16. The composition resulting from the combination of the        preceding ingredients.

In another embodiment, the invention provides a dentifrice comprising acrosslinked polyvinylpyrrolidone complexed with hydrogen peroxide,together with additional linear and/or crosslinked polyvinylpyrrolidone,and a dentifrice carrier.

For example, the invention provides Composition 2, a gel non-abrasivedentifrice comprising a crosslinked polyvinylpyrrolidone complexed withhydrogen peroxide, together with additional linear and/or crosslinkedpolyvinylpyrrolidone, e.g.,

-   -   2.1. Composition 1 wherein the whitening complex contains about        10-30%, e.g., 15-25%, for example about 17-22% of hydrogen        peroxide by weight, and about 5-45%, for example about 7-12%        total nitrogen by weight; for example, having substantially the        same specifications as Polyplasdone® XL-10, e.g., Polyplasdone®        XL-10F, e.g., available from International Specialty Products        (Wayne, N.J.);    -   2.2. Composition 2 or 2.1 wherein the total amount of hydrogen        peroxide by weight of the composition is 0.5-3%, e.g.,        0.75-1.5%, e.g. about 1%;    -   2.3. Any of the foregoing compositions which contains less than        3% water, e.g., less than 1% water, e.g., is substantially        anhydrous;    -   2.4. Any of the foregoing compositions comprising polymer        thickeners selected from (i) polyethylene glycol, (ii)        polyethylene glycol-polypropylene glycol block co-polymers        having a molecular weight of at least 5000, and (iii)        combinations thereof;    -   2.5. The preceding composition comprising an ethylene oxide,        propylene oxide block co-polymer of formula (ethylene        oxide)_(x)-(propylene oxide)_(y) wherein x is an integer of        80-150, e.g. 100-130, e.g. about 118, and y is an integer 30-80,        e.g., about 60-70, e.g. about 66, having an average molecular        weight of greater than 5000, e.g., 8000-13000 Da, e.g. about        9800;    -   2.6. The preceding composition additionally comprising        polyethylene glycol of average molecular weight 400 to 800,        e.g., about 600 Da;    -   2.7. Any of the foregoing compositions additionally comprising        humectants, e.g. selected from glycerin, propylene glycol or a        combination thereof;    -   2.8. Any of the foregoing compositions additionally comprising,        a tartar control agent, e.g., selected from tetrasodium        pyrophosphate (TSPP) and sodium tripolyphosphate (STPP);    -   2.9. Any of the foregoing compositions additionally comprising a        surfactant, e.g., sodium lauryl sulfate (SLS);    -   2.10. Any of the foregoing compositions additionally comprising        an antibacterial agent, e.g., triclosan;    -   2.11 Any of the foregoing compositions additionally comprising        an antioxidant, e.g., butylated hydoxytoluene (BHT);    -   2.12. Any of the foregoing compositions comprising any or all of        the following ingredient classes and/or particular ingredients        by weight:

Humectants 50-70%, e.g. Glycerin 40-55%, e.g. about 47% Propylene glycol10-20%, e.g., about 15% Fumed silica 0-2% Polymers 10-40%, e.g.,Ethylene oxide, propylene oxide 1-15%, e.g., about 5% block co-polymer,avg. MW >5 kDa Polyethylene glycol 600 5-15%, e.g., about 10%Polyvinylpyrrolidone 1-20%, e.g., about 10% Whitener, 3-10%, e.g.,Crosslinked polyvinylpyrrolidone 3-10%, e.g., about 5.5% complexed with15-25% hydrogen peroxide Fluoride, 0-1%, e.g. Sodium monofluorophosphate0.5-1%, e.g., about 0.76% Surfactant, 0-5%, e.g. SLS 1-3%, e.g., about2% Tartar control agent, e.g. TSPP 0.5-5%, e.g., about 2% Antioxidant,0.01-5%, e.g. BHT 0.03%  Flavorings 0.1-5%   Water  <3%

-   -   2.13. The composition resulting from the combination of the        preceding ingredients.

In some embodiments, the present invention provides oral carecompositions comprising: a crosslinked polyvinylpyrrolidone complexedwith hydrogen peroxide, a stabilizing amount of an additional linearand/or crosslinked polyvinylpyrrolidone, an abrasive and a humectant.

Some embodiments provide oral care compositions comprising: from about0.5 to about 16.5%, by weight, crosslinked polyvinylpyrrolidonecomplexed with hydrogen peroxide. Other embodiments provide oral carecompositions comprising: from about 1 to about 15%, by weight, crosslinked polyvinylpyrrolidone complexed with hydrogen peroxide. Stillother embodiments provide oral care compositions comprising: from about3 to about 12%, by weight, crosslinked polyvinylpyrrolidone complexedwith hydrogen peroxide. Yet other embodiments provide oral carecompositions comprising: from about 4 to about 10%, by weight,crosslinked polyvinylpyrrolidone complexed with hydrogen peroxide. Whileother embodiments provide oral care compositions comprising: from about5 to about 8%, by weight, crosslinked polyvinylpyrrolidone complexedwith hydrogen peroxide. In some embodiments, the oral care compositionscomprise 5.5%, by weight, crosslinked polyvinylpyrrolidone complexedwith hydrogen peroxide.

In some embodiments, the present invention provides oral carecompositions comprising from about 1 to about 20% of an additionallinear and/or crosslinked polyvinylpyrrolidone. Some embodiments providecompositions comprising from about 1 to about 15% by weight, of anadditional linear and/or crosslinked polyvinylpyrrolidone. Someembodiments provide compositions comprising from about 5 to about 15%,by weight, of an additional linear and/or cross linkedpolyvinylpyrrolidone. Other embodiments provide compositions comprisingfrom about 7 to about 12%, by weight, of an additional linear and/orcrosslinked polyvinylpyrrolidone. Further embodiments provide oral carecompositions comprising from about 8 to about 11%, by weight, of anadditional linear and/or crosslinked polyvinylpyrrolidone. Still furtherembodiments provide compositions comprising from about 8.5 to about 10%,by weight, of an additional linear and/or crosslinkedpolyvinylpyrrolidone. Still other embodiments provide oral carecompositions comprising 9.9% or 10%, by weight, of an additional linearand/or crosslinked polyvinylpyrrolidone. Yet other embodiments provideoral care compositions comprising about 9%, by weight, of an additionallinear and/or crosslinked polyvinylpyrrolidone.

Some embodiments of the present invention provide gel-based peroxidecompositions further comprise a calcium abrasive. In some embodiments,the compositions comprise from about 9 to about 25%, by weight propyleneglycol. In some embodiments, the compositions comprise from about 14 toabout 32%, by weight, glycerin. In other embodiments, the compositionscomprise less than 20%, by weight, of a calcium abrasive. Someembodiments provide compositions comprising from about 9 to about 25%,by weight, propylene glycol; from about 14 to about 32%, by weight,glycerin; and less than 20%, by weight, of a calcium abrasive.

Still other embodiments provide oral care compositions comprising fromabout 20 to about 60%, by weight, humectant.

Yet further embodiments provide oral care compositions comprising fromabout 5 to about 15%, by weight, abrasive.

The compositions of the invention a “low water” content, meaning that atotal concentration of water, including any free water and all watercontained in any ingredients, is less than about 5%, preferably lessthan 3%, preferably less than 2% water.

Where abrasives are present, the average particle size is generallyabout 0.1 to about 30 microns, for example about 1 to about 20 or about5 to about 15 microns.

In various embodiments of the present invention, the oral compositioncomprises an anticalculus (tartar control) agent. Generally, tartarcontrol agents are categorized as being incompatible with some whiteningagents, but embodiments of the present invention incorporate tartarcontrol agents and whitening agents in a single phase whiteningcomposition. Suitable anticalculus agents include without limitationphosphates and polyphosphates (for example pyrophosphates),polyaminopropanesulfonic acid (AMPS), hexametaphosphate salts, zinccitrate trihydrate, polypeptides, polyolefin sulfonates, polyolefinphosphates, diphosphonates. The anticalculus agent is present at about0.1% to about 30%. The oral composition may include a mixture ofdifferent anticalculus agents. In one preferred embodiment, tetrasodiumpyrophosphate (TSPP) and sodium tripolyphosphate (STPP) are used. Theanticalculus agent comprises TSPP at about 1-2% and STPP at about 7% toabout 10%.

The oral care composition can optionally include at least one orallyacceptable source of fluoride ions. Any known or to be developed in theart may be used. Suitable sources of fluoride ions include fluoride,monofluorophosphate and fluorosilicate salts. One or more fluorideion-releasing compound is optionally present in an amount providing atotal of about 100 to about 20,000 ppm, about 200 to about 5,000 ppm, orabout 500 to about 2,500 ppm, fluoride ions.

The compositions of the invention may also comprise various dentifriceingredients to adjust the rheology and feel of the composition such ashumectants, surface active agents, thickening or gelling agents, etc.

The compositions of the present invention may comprise a surface activeagent (surfactant). Suitable surfactants include without limitationWater-soluble salts of C₈₋₂₀ alkyl sulfates, sulfonated monoglyceridesof fatty acids, sarcosinates, taurates sodium lauryl sulfate, sodiumcocoyl monoglyceride sulfonate, sodium lauryl sarcosinate, sodium laurylisoethionate, sodium laureth carboxylate and sodium dodecylbenzenesulfonate, and cocoamidopropyl betaine.

The compositions of the present invention optionally comprise athickener. Any orally acceptable thickening agent can be used, includingwithout limitation carbomers, also known as carboxyvinyl polymers,carrageenans, also known as Irish moss and more particularly—carrageenan(iota-carrageenan), high molecular weight polyethylene glycols (such asCARBOWAX®, available from The Dow Chemical Company), cellulosic polymerssuch as hydroxyethylcellulose, carboxymethylcellulose (CMC) and saltsthereof, e.g., CMC sodium, natural gums such as karaya, xanthan, gumarabic and tragacanth, colloidal magnesium aluminum silicate, andcolloidal and/or fumed silica and mixtures of the same. One or morethickening agents are optionally present in a total amount of about 0.1%to about 90%, for example about 1% to about 50% or about to about 35%.

In various preferred embodiments, the carrier may comprise polymersand/or copolymers of polyethylene glycol, of ethylene oxide/propyleneoxide, and of silicone. If such copolymers/polymers are used, they maybe selected from commercially available materials. Block copolymers ofethylene oxide/propylene oxide are useful, but higher molecular weight,e.g., >5000 Da are preferred, e.g. including PLURACARE® L1220 (availablefrom BASF, Wyandotte, Mich., United States of America). Low or mediummolecular weight polyethylene glycol, e.g., PEG 400, PEG 600, PEG 800,PEG 1000 and mixtures thereof are also useful. It is preferred that thecarrier(s) provide a dentifrice with a viscosity of about 10,000 CPS toabout 700,000 CPS, preferably about 30,000 CPS to about 300,000 CPS.

As recognized by one of skill in the art, the oral compositions of thepresent invention optionally include other materials, such as forexample, anti-caries agents, desensitizing agents, viscosity modifiers,diluents, surface active agents, such as surfactants, emulsifiers, andfoam modulators, pH modifying, agents, abrasives, in addition to thoselisted above, humectants, mouth feel agents, sweetening agents, flavoragents, colorants, preservatives, and combinations thereof, it isunderstood that while general attributes of each of the above categoriesof materials may differ, there may be some common attributes and angiven material may serve multiple purposes within two or more of suchcategories of materials. Preferably, the carrier is selected forcompatibility with other ingredients of the composition.

Flavorants, sweeteners, colorants, foam modulators, mouth-feel agentsand others additively may be included if desired, in the composition.

The compositions of the present invention optionally comprise one ormore further active material(s), which is operable for the prevention ortreatment of a condition or disorder of hard or soft tissue of the oralcavity, the prevention or treatment of a physiological disorder orcondition, or to provide a cosmetic benefit.

The compositions may include a stannous ion or a stannous ion source.Suitable stannous ion sources include without limitation stannousfluoride, other stannous halides such as stannous chloride dihydrate,stannous pyrophosphate, organic stannous carboxylate salts such asstannous formate, acetate, gluconate, lactate, tartrate, oxalate,malonate and citrate, stannous ethylene glyoxide and the like. One ormore stannous ion sources are optionally and illustratively present in atotal amount of about 0.01% to about 10%, for example about 0.1% toabout 7% or about 1% to about 5%.

The compositions of the present invention optionally comprise anantimicrobial (e.g., antibacterial) agent. A further illustrative listof useful antibacterial agents is provided in such as those listed inU.S. Pat. No. 5,776,435 to Gaffar et al., the contents of which areincorporated herein by reference. One or more antimicrobial, agents areoptionally present in an antimicrobial effective total amount, typicallyabout 0.05% to about 10%, for example about 0.1% to about 3%.

The compositions of the present invention optionally comprise anantioxidant. Any orally acceptable antioxidant can be used, includingbutylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), vitaminA, carotenoids, vitamin E, flavonoids, polyphenols, ascorbic acid,herbal antioxidants, chlorophyll, melatonin, and mixtures thereof.

The compositions of the present invention optionally comprise asialagogue or saliva-stimulating agent, an antiplaque agent, ananti-inflammatory agent, and/or a desensitizing agent.

While ingredients are sometimes identified herein by category, e.g.,humectant, antioxidant, thickener, etc., this identification is forconvenience and clarity, but is not intended to be limiting. All of theingredients in the compositions may have functions in addition to theirprimary function, and may contribute to the overall properties of thecomposition, including its stability, efficacy, consistency, mouthfeel,taste, odor and so forth.

Methods are provided to whiten an oral surface in a human or animalsubject comprising storing in stable form a composition of theinvention, e.g., Composition 1, et seq. or Composition 2, et seq. asdescribed above, and contacting said composition with the oral surface.As used herein “animal subject” includes higher order non-human mammalssuch as canines, felines, and horses. The oral care composition iscontacted with an oral surface of the mammalian subject to therebywhiten teeth in a highly efficacious manner, without any negativeinteraction between the whitening agent, the peroxide incompatibleabrasive, and other ingredients.

In various embodiments, it is preferred that the oral care compositionis applied and contacted with the oral surface. The dentifrice, preparedin accordance with the present invention is preferably applied regularlyto an oral surface, preferably on a daily basis, at least one time dailyfor multiple days, but alternately every second or third day. Preferablythe oral composition is applied to the oral surfaces from 1 to 3 timesdaily, for at least 2 weeks up to 8 weeks, from four months to threeyears, or more up to lifetime.

In some embodiments, the diameter of the top of the tube in which the acomposition of the present invention is packaged, expands less than 0.1cm, after 1 week of aging at 60° C. In some embodiments, the diameter ofthe top of the tube in an oral care composition of the present inventionis packaged, expands less than 0.05 cm, after 1 week of aging at 60° C.In other embodiments, the diameter of the top of the tube in which acomposition of the present invention is packaged, expands less than 0.04cm, after 1 week of aging at 60° C. In further embodiments, the diameterof the top of the tube in which a composition of the present inventionis packaged, expands less than 0.03 cm, after 1 week of aging at 60° C.In other embodiments, the diameter of the top of the tube in which acomposition of the present invention is packaged, expands less than 0.02cm, after 1 week of aging at 60° C. In yet other embodiments, thediameter of the top of the tube in which a composition of the presentinvention is packaged, expands less than 0.01 cm, after 1 week of agingat 60° C. While in other embodiments, the diameter of the top of thetube in which a composition of the present invention is packaged, doesnot expand to a measurable extent.

In some embodiments, the compositions of the present invention do notexhibit an unacceptable level of phase separation after 30 minutes at2050 rpm in a LumiSizer 110 analytical centrifuge. In other embodiments,the compositions of the present invention do not exhibit an unacceptablelevel of phase separation after 35 minutes at 2050 rpm in a LumiSizer110 analytical centrifuge. In further embodiments, the compositions ofthe present invention do not exhibit an unacceptable level of phaseseparation after 40 minutes at 2050 rpm in a LumiSizer 110 analyticalcentrifuge. In still further embodiments, the compositions of thepresent invention do not exhibit an unacceptable level of phaseseparation after 45 minutes at 2050 rpm in a LumiSizer 110 analyticalcentrifuge. In yet other embodiments, the compositions of the presentinvention do not exhibit an unacceptable level of phase separation after50 minutes at 2050 rpm in a LumiSizer 110 analytical centrifuge. In someembodiments, the compositions of the present invention do not exhibit anunacceptable level of phase separation after 55 minutes at 2050 rpm in aLumiSizer 110 analytical centrifuge. Still other embodiments providecompositions that do not exhibit an unacceptable level of phaseseparation after 60 minutes at 2050 rpm in a LumiSizer 110 analyticalcentrifuge. While other embodiments provide compositions that do notexhibit an unacceptable level of phase separation after 65 minutes at2050 rpm in a LumiSizer 110 analytical centrifuge. In some embodiments,the compositions of the present invention do not exhibit an unacceptablelevel of phase separation after 70 minutes at 2050 rpm in a LumiSizer110 analytical centrifuge. In some embodiments, the compositions of thepresent invention do not exhibit an unacceptable level of phaseseparation after 75 minutes at 2050 rpm in a LumiSizer 110 analyticalcentrifuge. In some embodiments, the compositions of the presentinvention do not exhibit an unacceptable level of phase separation after80 minutes at 2050 rpm in a LumiSizer 110 analytical centrifuge. In someembodiments, the compositions of the present invention do not exhibit anunacceptable level of phase separation after 85 minutes at 2050 rpm in aLumiSizer 110 analytical centrifuge. In some embodiments, thecompositions of the present invention do not exhibit an unacceptablelevel of phase separation after 90 minutes at 2050 rpm in a LumiSizer110 analytical centrifuge. In some embodiments, the compositions of thepresent invention do not exhibit an unacceptable level of phaseseparation after 95 minutes at 2050 rpm in a LumiSizer 110 analyticalcentrifuge. In some embodiments, the compositions of the presentinvention do not exhibit an unacceptable level of phase separation after100 minutes at 2050 rpm in a LumiSizer 110 analytical centrifuge. Insome embodiments, the compositions of the present invention do notexhibit an unacceptable level of phase separation after 105 minutes at2050 rpm in a LumiSizer 110 analytical centrifuge. In some embodiments,the compositions of the present invention do not exhibit an unacceptablelevel of phase separation after 110 minutes at 2050 rpm in a LumiSizer110 analytical centrifuge. In some embodiments, the compositions of thepresent invention do not exhibit an unacceptable level of phaseseparation after 115 minutes at 2050 rpm in a LumiSizer 110 analyticalcentrifuge. In some embodiments, the compositions of the presentinvention do not exhibit an unacceptable level of phase separation after120 minutes at 2050 rpm in a LumiSizer 110 analytical centrifuge. Insome embodiments, the compositions of the present invention do notexhibit an unacceptable level of phase separation after 125 minutes at2050 rpm in a LumiSizer 110 analytical centrifuge.

In some embodiments, the diameter of the top of the tube in which acomposition of the present invention is packaged, expands less than0.01% of the top diameter of the tube, after 1 week of aging at 60° C.In some embodiments, the diameter of the top of the tube in which acomposition of the present invention is packaged, expands less than0.05% of the top diameter of the tube, after 1 week of aging at 60° C.In some embodiments, the diameter of the top of the tube in which acomposition of the present invention is packaged, expands less than 0.1%of the top diameter of the tube, after 1 week of aging at 60° C. In someembodiments, the diameter of the top of the tube in which a compositionof the present invention is packaged, expands less than 0.5% of the topdiameter of the tube, after 1 week of aging at 60° C. In someembodiments, the diameter of the top of the tube in which a compositionof the present invention is packaged, expands less than 1% of the topdiameter of the tube, after 1 week of aging at 60° C. In someembodiments, the diameter of the top of the tube in which a compositionof the present invention is packaged, expands less than 3% of the topdiameter of the tube, after 1 week of aging at 60° C. In someembodiments, the diameter of the top of the tube in which a compositionof the present invention is packaged, expands less than 5% of the topdiameter of the tube, after 1 week of aging at 60° C. In someembodiments, the diameter of the top of the tube in which a compositionof the present invention is packaged, expands less than 10% of the topdiameter of the tube, after 1 week of aging at 60° C. In someembodiments, the diameter of the top of the tube in which a. compositionof the present invention is packaged, expands less than 15% of the topdiameter of the tube, after 1 week of aging at 60° C. In someembodiments, the diameter of the top of the rube in which a compositionof the present invention is packaged, expands less than 20% of the topdiameter of the tube, after 1 week of aging at 60° C.

In some embodiments, the diameter of the top of the tube in which acomposition of the present invention is packaged, expands less than 25%of the top diameter of the tube, after 1 week of aging at 60° C. Inother embodiments, the diameter of the top of the tube in which acomposition of the present invention is packaged, expands less than 30%of the top diameter of the tube, after 1 week of aging at 60° C. In someembodiments, the diameter of the top of the tube in which a compositionof the present invention is packaged, expands less than 35% of the topdiameter of the tube, after 1 week of aging at 60° C. In someembodiments, the diameter of the top of the tube in which a compositionof the present invention is packaged, expands less than 40% of the topdiameter of the tube, after 1 week of aging at 60° C. in someembodiments, the diameter of the top of the tube in which a compositionof the present invention is packaged, expands less than 45% of the topdiameter of the tube, after 1 week of aging at 60° C. In someembodiments, the diameter of the top of the tube in which a compositionof the present invention is packaged, expands less than 50% of the topdiameter of the tube, after 1 week of aging at 60° C.

The invention is illustrated in the following non-limiting examples.

EXAMPLES Example 1

A gel dentifrice having a peroxide composition of about 1% is preparedhaving the following ingredients:

TABLE 1 Ingredient % (w/w) 85% syrupy phosphoric acid 0.2 PEG₁₁₈/PPG₆₆co-polymer 5 Glycerin 47 Propylene glycol 15 PEG 600 10 PVP 10Crosslinked PVP/H₂O₂ 5.5 TSPP 2 Sucralose 0.05 Sodium saccharine 0.6Sodium monofluorophosphate 0.76 Sodium lauryl sulfate 2 BHT 0.03 Mintflavor 2

Example 2

A get dentifrice having a peroxide composition of about 1% is preparedhaving the following ingredients:

TABLE 2 Ingredient % (w/w) 85% syrupy phosphoric acid 0.2 Glycerin 25.36PEG₁₁₈/PPG₆₆ co-polymer 7.5 PEG 600 10 Propylene glycol 25 CrosslinkedPVP/H₂O₂ 5.5 TSPP 2 Sucralose 0.05 Sodium saccharin 0.6 Sodiummonofluorophosphate 0.76 Calcium pyrophosphate 10 PVP 9 BHT 0.03 Flavor2 Sucralose 0.05 Sodium lauryl sulfate 2

Example 3

A toothpaste having a peroxide content of about 1% is prepared with thefollowing ingredients:

TABLE 3 Ingredient % (w/w) 85% syrupy phosphoric acid 0.2 PEG₁₁₈/PPG₆₆co-polymer 10 Glycerin 5 PEG 600 10 Propylene glycol 25 CrosslinkedPVP/H₂O₂ 5.5 TSPP 2 Sucralose 0.05 Sodium saccharine 0.6 Sodiummonofluorophosphate 0.76 Calcium pyrophosphate 35 Fumed silica 1.5 BHT0.03 Mint flavor 2.25

Example 4

The in vitro whitening efficacy of the compositions of Examples 1 and 3are tested versus commercial whitening dentifrices.

Brushing Test:

The in vitro whitening efficacy of the products is tested by brushingexperiments. Bovine teeth are prophy stained to achieve similar initiallightness values. The bovine teeth are mounted in a tray for brushingstudy. A 1:1 slurry of dentifrice to deionized water is prepared and 25grams added to brushing tray. The stained bovine teeth are brushed forfor 20 minutes at 120 strokes/mm. This is intended to approximate oneweek of bushing (1.5 min brushing, twice a day for seven days=21minutes/week). Teeth are rinsed with 100 g deionized water, then thecolor (L*a*b*values) is measured with a spectrophotometer. This isrepeated three times.

The spectrophotometer used is Spectroshade from MHT. The measurementscale is the CIE L*a*b* (CIELAB) scale developed by the InternationalCommission on Illumination (CIE). CIELAB is an opponent color systembased on the fact that retinal color stimuli are translated intodistinctions between light and dark, red and green, and blue and yellow.CIELAB indicates these values with three axes: L*, a*, and b*. The Lvalue indicates the lightness of a color, where L=0 is black and L=100is white. ΔL=L_(brushed)−L_(initial). Thus, a larger positive ΔLvalue=whiter teeth. The as value ranges between +a=magenta and −a=green.The b value ranges between +b=yellow and −b=blue. The W valueincorporates the L, a and b values to describe bow close the measuredcolor is to true white, where W*=(a2+b2+(L*−100)2)½. A larger negativeΔW value corresponds to greater whitening.

In comparing the toothpaste formulation of Example 3 with a leadingcommercial whitening toothpaste (Brand A), the formulation of Example 3shows significantly greater whitening:

TABLE 4 ΔL using Brand A and Example 3: 20 mins 40 mins 60 mins 80 minsBrand A 2.1 + 0.6 3.1 + 0.7 3.6 + 0.6 3.8 + 1.0 Example 3 4.4 + 0.95.4 + 0.9 6.5 + 1.0 7.5 + 0.9

TABLE 5 ΔW using Brand A and Example 3: 20 mins 40 mins 60 mins 80 minsBrand A −2.2 + 0.5 −3.1 + 0.6 −3.5 + 0.4 −3.6 + 0.9 Example 3 −4.0 + 0.9−4.8 + 1.4 −6.1 + 1.6 −7.0 + 1.3

Similar results are obtained with the gel of Example 1. After fourcycles of brushing (80 minutes), the ΔL and ΔW are as follows:

TABLE 6 ΔL and ΔW using Brand A and Example 1 ΔL ΔW Brand A 3.8 + 1.0−3.6 + 0.9 Example 1 7.3 + 2.6 −6.0 + 2.8

Bleaching Test:

Hard abrasive particles serve to break up the stain during the act ofbrushing when they are rubbed against the stain by the bristles of thetoothbrush. Peroxide whitens both extrinsic (surface stains) andintrinsic stains (below the surface of enamel) through a chemicalreaction in which the unsaturated bonds in colored stain molecules areoxidized by peroxide to become colorless. In this test method stainedhydroxyapatite disks are soaked in dentifrice slurry. As disks aresoaked, rather than brushed, stains will be bleached by toothpastecontaining peroxide but should not be removed by toothpastes containingonly abrasives. The substrate used is 1″ diameter hydroxyapatite (HAP)disks (human enamel is ˜96% hydroxyapatite by weight; human dentin is˜70% hydroxyapatite by weight). The HAP are stained using a mixture ofcommon foods that stain teeth: 1 part 1% instant coffee solution(Maxwell House), 1 part brewed black tea (Lipton Black Tea soaked for 2min in hot water), 1 part red wine (Cabernet). The HAP disks are soakedovernight in artificial saliva. The saliva treated disks are soaked instaining solution for 2 hrs, rinsed with water, and dried. The disks arethen soaked in a stirring dentifrice shiny for 2 min, rinsed with waterand dried.

TABLE 7 ΔW using Brand A and Example 1 in bleaching test; stained HAPdisks soaked in 1:2 dentifrice to water slurry for 2 min L a b W* ΔWControl 80.17 5.51 6.18 21.49 Brand A 85.79 3.02 4.24 15.13 −6.36Example 1 95.43 0.07 1.61 4.85 −16.64

Example 1 is then further tested versus a commercially available 1%peroxide toothpaste (Brand B).

TABLE 8 ΔW for Example 1 versus Brand B in a bleaching test; stained HAPdisks soaked in a 1:1 dentifrice to water slurry for 2 minutes. L a b W*ΔW Control 79.59 5.52 6.43 22.10 Example 1 96.61 −.31 1.37 3.67 −18.43Brand B 96.36 −.91 3.45 5.10 −17.00

The data described in Table 8 indicates that an exemplary composition ofthe present invention provides a significant improvement in ΔW over acommercially available 1% peroxide toothpaste.

Example 5

The objective of the consumer test is to determine how the two testformulas with peroxide compare in consumer preference and whiteningperformance after 2 weeks of use vs. the leading peroxide andnonperoxide competition.

Two Week Results:

Both Examples 1 and 3 deliver higher % of noticeable whitening amongstconsumers who perceived their teeth to be whiter vs. Brand A after 1week of use [71% for Example 1 (1% gel), 77% for Example 3 (1% paste),58% for Brand A]. Also two statements come up higher for both Examplesthan for Brand A: “This toothpaste gives me 360 degree coverage for anall over white” and “This toothpaste is the most convenient way to getnoticeably whiter teeth in just 1 week”. Both Examples weresignificantly better than Brand B in overall and taste liking.

Example 6

The toothpaste of Example 3 is tested for stability versus acommercially available 1% peroxide toothpaste. Peroxide-containingcompositions which bloat to an unacceptable extent would not be expectedto provide the level of whitening suitable for a toothpaste composition.

Tube Bloating:

The diameter of the tube is measured at the bottom (close to cap), themidpoint, and the top (close to crimp), before and after 1 week of agingat 60° C. The elevated temperature accelerates the aging, approximatingthe degree of degradation that can be expected to occur over long-termstorage at room temperature.

TABLE 9 Top Middle Bottom Set 1 Set 2 Set 1 Set 2 Set 1 Set 2 (change(change (change (change (change (change in cm) in cm) in cm) in cm) incm) in cm) Example 3 0.02 0.00 0.20 0.10 0.10 −0.20 Brand B 0.10 0.200.10 0.20 −0.10 0.20

Physical Separation:

Samples are centrifuged using an analytical centrifuge (LumiSizer 110from L.U.M. GmbH, Berlin), which measures separation of the product bymeasuring optical transmission through the tube as a function of time.

The results show that it takes longer for Example 3 to separate thanBrand B:

TABLE 10 Sample Example 3 Brand B Time to Separation at 133 ± 5 40 ± 102050 rpm (mins)

Example 7 Bloating Study

a bloating study was also conducted on gel based abrasive containingcompositions of the present invention to evaluate their chemicalstability profiles. Unexpectedly, the gel based abrasive containingcompositions of the present invention which comprise from about 9 toabout 25%, by weight, propylene glycol; from about 14 to about 32%, byweight, glycerin; and from about 1 to about 15%, by weight, of anadditional linear and/or cross linked polyvinylpyrrolidone, do not bloatto an unacceptable extent after 1 week of aging at 60° C.

The data described in the Examples evidences the unexpected improvementin chemical and physical stability demonstrated by compositions of thepresent invention.

While particular embodiments of the present invention have beenillustrated and described, it will be obvious to those skilled in theart that various changes and modifications may be made without departingfrom the spirit and scope of the invention. It is therefore intended tocover in the appended claims all such changes and modifications whichare within the scope of the invention.

The invention claimed is:
 1. A dentifrice composition comprising (i) awhitening complex comprising crosslinked polyvinylpyrrolidone complexedwith hydrogen peroxide, wherein the whitening complex contains about10-30% hydrogen peroxide, by weight, and the whitening complex containsabout 5-15% total nitrogen by weight, (ii) an ethylene oxide, propyleneoxide block co-polymer of average molecular weight greater than 5000 Da,wherein the ethylene oxide, propylene oxide block co-polymer comprises(ethylene oxide)_(x)-(propylene oxide)_(y) wherein x is an integer of80-150 and y is an integer 30-80; (iii) 5 to 15% by weight ofpolyethylene glycol of average molecular weight 400 to 800 Da; (iv) 3 to7% by weight of glycerin; (v) 20 to 30% by weight of propylene glycol;(vi) sodium lauryl sulfate; and (vii) sodium monofluorophosphate;wherein the total amount of hydrogen peroxide by weight of thecomposition is 0.5-3%, and the composition comprises less than 3% waterby weight.
 2. The composition of claim 1 which is a toothpastecomprising a calcium abrasive selected from a calcium phosphate salt andcalcium carbonate.
 3. The composition of claim 2 wherein the calciumabrasive comprises calcium pyrophosphate.
 4. The composition of claim 3comprising the following ingredients by weight: a. Glycerin  3-7% b.Propylene glycol 20-30% c. Ethylene oxide, propylene oxide  5-15% blockco-polymer, avg. MW >5 kDa d. Polyethylene glycol 600  5-15% e.Crosslinked polyvinylpyrrolidone 3-16.5%  complexed with 15-25% H₂O₂ f.Calcium pyrophosphate 25-45%.


5. The composition of claim 1, further comprising additional linearand/or crosslinked polyvinylpyrrolidone.
 6. The composition of claim 5,wherein the additional linear and/or crosslinked polyvinylpyrrolidone ispresent at a concentration of 1-20%, by weight.
 7. A compositionaccording claim 1, further comprising stannous fluoride.
 8. Acomposition according claim 1, further comprising zinc citrate.
 9. Acomposition according claim 1, further comprising stannous fluoride andzinc citrate.
 10. The composition according to claim 1, wherein thesodium monofluorophosphate is present in an amount providing 200 to 5000ppm of fluoride ions.
 11. The composition according to claim 1, whereinthe sodium monofluorophosphate is present in an amount of 0.5 to 1% byweight.
 12. The composition according to claim 1, wherein the sodiumlauryl sulfate is present in an amount of 1 to 3% by weight.